The numbers tell part of the story.

Twelve hundred and fifty feet above the ground, views stretching 50 miles on a clear day.

Almost a decade of rebuilding and yet once you are up here, even on a cloudy day, those numbers give way to feelings which are quite frankly difficult to describe.

Rumor has it that when it's clear, you can see the curvature of the earth from this point and it's certainly true that you can feel the weight of recent history.

The construction of this building and the observatory are a fist pump for going forward, for moving forward, for saying, " There is a future and we embrace it."

Dave Checketts is the man in charge of the day-to-day running of the observatory.

Architect TJ Gottesdiener helped design the structure itself.

It pulls at you when you are up there and you start, you look down and you can see the memorial, you have that sense of remembrance.

It's not just about the views. The 47 second elevator ride comes complete with a 500 year time lapse of New York skyline.

And now you get a brief view of the World Trade Center on this side just for, just a moment and then it disappears.

And then the view itself is revealed gradually behind automatic screens.

In a city crowded with skyscrapers, One World Trade Center has serious competition.

How many visitors a year?

Last year we had 4.3 million.

The Empire State Building 's observatory brought in revenues of 111 million last year.

New York City is represented to so many people in the world by the Empire State Building.

Few would dispute One World Trade Center now shares that status and with a predicted 3. 8 million visitors a year to the observatory, it could well match that success.

For those involved in the project though, it already has.

When I walk by the building now, it feels right.